Compressor



Y v EQBRUAND. l l" l COMPRESSOR.

APRLICATION ILED APR.29| 19l9.

.7 SHEETS-SHEET 2.

' Patented Mf.9,'1920. 1 l

E. BRUAND.

COMPRESSOR.

APPLICATION FlLED APR. 2.9. |9l9.

3,333,382. Patented Mar. 9,1920.

A7 SHEETS-SHEET 4- Ill/l -l yl E. BRUAND.

' COMPHEQSOL DPLlcATloN FILED APR. 29. |919.

Patented Mar. 9, 1920.

E. BRUAND.

COMPRESSOR.

APyLlcATloN min APR, 29. ma.

PatntedMar. 9, 1920. 7 SHEETS- SHEET 6.

7 SHEETS-SHEET 7.

l l I o .30 Tag l. e6 7 9 l l w 15 5 i' 1 29p a .212

` A Ja@ Jaw@ l 3 I Y adda# l' O y am@ To all whom it may concern.'

Uivrriii STATES PATENT oFFioE..

EDOUARD BRUAND, 0F VILLENEUVE, SWITZERLAND.

COMPRESSOR; l

Specicatin of Letters Patent. Patented lVIaI. 9, 1920.

Application lcd April 29. 1919. Serial No; 293.561.

Be it known thatI, EDOUARD BRUAND, a citizen of Switzerland, residing atVilleneuve, Canton of Vaud, in the Confederation of Switzerlanth'haveinvented certain new and useful Improvements in and Relating toCompressors, of which theI following is a specification.

The subject matt-er of the present inven-l tion 1s a compressor.

It is distinguished from other known compressors by the fact that adouble acting piston operates inside a cylinder and in the interior ofwhich are contained a crank of a driving crank shaft and a connecting'rod connecting the crank to the piston.

Its cylinder may be provided with a single suction valve at each end.The suction valves are for instance normally operated by a cam, but arecapable of operation by other means when the pressure 1n the conn on therollers.

The above arrangement may be operative automatically under the influenceof the pressure of the compressed fluid. To this effect the memberadapted to turn about the axis' of rotation of the cam acting on therollers is operated, by way of example, in one direction by apistonsubjected to the pressure of the compressed fluid and operated bythe Y above pressure when the latter reaches the predetermined value,and in the other direction, by suitable return springs.l Furthermorethis arrangement may be constructed so as to produce the opening of thesuction valves during the com ression stroke of the piston, this openingtaking place however in such a way that there is a slight compression atthe end'of the stroke.

For instance the construction comprises,

on the one hand, a; piston serving, when-r subl jected to the action ofthe compressed luid,v to actuate the means for producingthe idle runningof the compressor; on Athe A other comprise ranged one in the other andact independ- Grooves in a member adapted to turn4 hand, a resilientmembrane subjected to the action' of the compressed fluid operates acontrol member, whereby either the atmospheric pressure or the pressureof the compressed luid acts on the piston. The con'- trolmenibeigconsisting of a 'slide valve, is. connected to a lever on whichare adapted to act, on one side of the axis about which Y said leverrotates, the resilient membrane, and on the other side a spring ofadjustable tension; a piston, which is also connected to the lever, maybe subjected to the action of the compressed fluid-in 'order tocompensate entirely or partially for any end pull exerted by said fluidon the -slide valve.

The cylinder maybe provided with auj tomaticdelivery valves, each ofwhich may two valve bodies which are arently of one another. n f

The cylinder may be provided with a system of lubrication under pressureand-a system for circulating cooling water around the bodyV thereof or1n the heads thereof and around the seats of the suction and deliveryvalves. It may be cast in one piece with a base' of the compressor,which provides a space' for the fluid drawn in and channels.

for the compressed fluid, .as well .as for the cooling water. 2

- Y In the drawing:

Figure 1 is a side elevation of thecompresser comprising my presentinvention. f Fig. `2 is an end elevation of the same.

Fig. 3 is a plan ofthe compressor.

Fig. 4 is a central longitudinal vertical cross sectionof thecompressor. y

Fig. 5 visa transverse cross section.

Fig. 6 is a sectional elevation of the partsfor operating the inletvalves.

- Fig. 7 is a sectional plan of the same.

Fig. 8 is a partial elevation illustrating the parts for operating thelintake valves with the same in a different position than that shown inFig. 6. Y

Fig. 9 is a sectional'view illustrating the check valve employed inl thecirculating system.'

Fig. 10'is a sectional view yillustrating the devices for controllingthe flow ofthe lubricant. Y

Fig. 11 is a partial elevationillustrating Y the reservoir for thelubricant.V f v Fig. 12 is a sectional view illustrating the v.discharge passages,

Fig. 13 is a similar view illustrating the intake passages.

Fig. 11 is a side elevation illustrating the parts employed forautomatically operating the intake valves. Fig. 15 is an enlargedcentral vertical sectionillustratng the parts for controlling theoperation of the intake valves, and

f Fig. 16 is a sectional view of a modified form lof delivery valve. l

`The cylinder a (see Figs. 1 to 5) in this formof the invention is castin one with a metal base and is provided with two removable heads al, a2carrying the positively operated suction or inlet valves b1, 'b2 andtheautomatic delivery valves c1, c2. cylinder there is a piston (Z whichhas two dissimilar-heads (l1, (Z2 of the same diameter :connected by amember Z3 of slightly smaller diameter and having lateral open ings d4,d5. YThrough the opening d5 passes a horizontal driving shaft ejou-rnaled in a bearing e2 which is carried by the cylinder a and isprovided eXternally with a driving pulley, (not` shown A.in the drawing)and with a crank el placed inside the piston and connectedV by aconnecting rod f to one of the heads Z2 thereof. A i

The air to be compressed enters the base through an inlet h1, passesintothe space h in the base (see Figs. 4, 5, 13) and passes by the ports 71,to the suction valves b1, b2. Each of these latter has a plate `b3provided with arod' b* whichslides in a guide bf fixedl in an opening inthe corresponding head al or a2.V Each rod b4 carries a washer beagainst which a spring 57 acts to close the valve and also against whichan operating lever z'l or 1'? acts. Each lever il, i? is pivoted at to abra-cket y' fixed to thecover a1 or a2 and is operated, notwithstandingthe action of the springs 727 by a pusher 701 or k2,

(see alsoFigs. G and '7) of rectangul:ir-cross section, sliding inguides Z1 parallel with the axis of the cylinder a. .Each pusher isprovided at that end opposite the levers i1 or with a roller 7c3normally in contact with a' cam Z on the shaft e. A spring or othermeans (not shown) acts on the pushers to maintain contact beWeen therollers 7a3 and the cam Z which operates the valve b1 or b2 to open thesame atthe desired moment and also permits them to close again for thecompression stroke.

I also employ devices so constructed as to automatically produce theopening of the suction valves 1, b2 during the compression stroke whenthe pressure in a reservoir into which the compressed. air is deliveredattains a predetermined value. To this end a cam m (see Figs. "G, 7 and8) is fixed on the shaft e behind the cani Zand is in contact with tworollers-yn.` diametrically opposite each other and mountedv .on spindles.nl adapted to move in radial guides o1 of a tric with the shaft e.

In thisV member 0 which rocks on-a bearing concen- The faces of the camsZ, m are designed in such a way that they1 may be included in one andthe same member. W hen the member o is in the position shown in Fig. 6,the rollers vn are not in engagement with the rollers 7c3 and cannoteXert any action on them, so that these rollers 7c3 merely follow oneface of the cams Z, m, but when the member 0 is moved to the positionyshown in Fig. 8 in which'the two guides o1 are horizontal, theyinterposc themselves at intervals between the rollers 7c3, which arewide enough to be able to be brought into contact with them, and the camm and cause the opening of the suction valves b1, 712' during thesuction and compression strokes. The face of the cam m is neverthelessso designed that a slight compression is produced at the en d of thestroke for the purpose of obviatingl blows'between the valves and theends of the piston and to protect the joints at each change of directionof travel of the piston (I. The opening ot' the suction valves duringthe compression strokes causes a scavenging ofthe cylinder. The member 0carries an arm o2 (see also Figs. 1, 3, and 7) in which is cut a slot 03for a pin p1 secured to a piston p moving in a .cylinder 1], which bymeans of a pipe fr is in communication with a special apparatus for thecontrol of the communicationY between cylinder q and the compressed airchamber and between the cylinder Vand the outside air.

The special apparatuslFigs. 1l and 15) comprises a base plate 20 fixedon cylinder r] by means of two forked arms 21 anda neck 2()2 screwed onto the pipe r. eck 2O2 is in constant communication with a passage 221within a casting 22 fixed to the base plate 20 and provided with lateralports 223` 224 leading into a cylinder 222 in the casting 22. In acylindrical slide 23 fitted intosaid cylinder 222 there are providedpassage ways 231 leading into a peripheral groove 23 whichis adapted toregister with the port. holes 223. In'the lower position. of slide 23(asrepresented in Fig. 15) the passage ways 231 are closed while when ina raised position rsaidways are open and the groove 232 registers withthe port hole 223 so as to put the inside of cylinder f;into.communication with a passage 204 made in the base plate 2O andleading into a neck 20l connected by any suitable means with acompressed air chamber which is not shown in the drawing. IV-hen theslide 2?) is raised therefore the cylinder g is filled with compressedair. The portholes` 22%" are in constant communication' with a passagein the slide 23 in which there are also radial ports 23" by which anopen passage is provided when in proper position into openings (notshown in the drawing) in the casting 22 and leading iso the upperposition to fthe'initsideair. In the-'lower position ot the slide 2 3the cylinderg istherefore` inf communication with tlieatmosphere.

`The slide is connected at 2-11`to one end ot' a lever24 piv'joted'in'242,tthe other end of said lever being provided with a screw 24f1"bearing by iiieansof capv 2,5xr

against. a spring 25 located within an open cup 2G which is part ofthecasting 22. [Normally the lifting a'ction ot' the'spring 25 iscounterbalanced by a sliank'27 movable `in a guide V26,1 andl supportedvby a`ublocl'281`:

rigidly attached to a diaphragm 28 against which the air-,pressurewithin passage 20 acts. Between the hinge 241 and shan'k`27 a rod 29 ishinged at 244 to the lei'fer24 saidrod being fast l to a, piston 291.mounted in a cylinder casting 22.; .By meeting with the'heald 29?v ofthe cylinder 228'the piston 221 will stop the upWardinove-ment oi slide23; Furthermore the upper face ot' 4 the piston. may be subjected Vtothe pressure in the passagev 202 diie 'to the f actfthat vin ot' slide23 the groove h232 communicates with aI port 22T 'connected by Vapassage 221" 'and a port inside of eylindeij225. y' v The operation 4ot'this apparatus is as followsz.

The tension ot spring 25 is regulated by means of the screw 24E soa'stofcounteiw balance the vupward pressure of the jaiiyin. the passage20'4 on diaphragm 28 when there 1 is a predetermined pressure in thecoinaction ott-he compressed-air ivitliin' passage 20* which acts onlyagainst a smallsiirtace of said slide. Therefore :the inside of cylindery]y `will communicate normally vwith the atmosphere through tlie`1`arts"r.202i 221,- "224, 233, 23, Spil'ingstA actingvonpinf )1 .maintainthe piston p `^in the position inc 'i- (i aiidftli'erollers n are intheir j that when tliecoinpressor is running normally. f "f At themoment when.hepre'ssurfof the rese'ryoir- Vand within the passage 20*reaches' thee predetermined' i'al'ue thej diap" riragrr'rA 28 iisesaiidcarriestheslianlr '27 into 'Contact the' "lever by the shank-Pissubstantially the same asfthatexertedjby- 228 which is also a part oftheofthe compressed aii" 22 with thev arev arranged f and of the arm o2(leverf 24', but the" pressure thus 'exertedv gainst ab' the spring 25l.and consequently the lever 24 will `not'fbe moved. f

If" the pressure' exceeds the "predetermined value the pressure on thediaphragm 28 will begr-eater than that of spring 25 and thev lever 24jwill `niove to compress the spring andraise the slide 23. After. theinitial upward movement of the slide S23-the air'fr'onr passage 20* actson agireatersurface. of the slide-and assists the "risingmoveme'nt As aresult of-` this movement the lgroove. 23?v reaches the: poits 223 f'and 227. ,When theV port223' isz'luncvered the interior otcylinder y isput` inw communication-with thecom'- )ressed air vessel, and tlietpistonp is vmoved rom right to left'as illustrated,'and therollers n comebetween cani m and rollerslt-, l.

so that the compressor will stop feeding the air in to said vessel.uncovered the Acompressed air enters cylinder 22B 'acting' downward onthefpiston therein.

"Phisfpressureil will nearly fcounterbalance that against tliefbotwmtace-sidefof slide 23 When the .port 227 is i and-W il1v therefore not:interfere with the y sensitiveness ofthe apparatus. Y. f vf i "Assoon'astlie pressure in the compressed air-vessel vfalls to its normalpoint the spring 25 .moves baekthe lever .2l and the slide 23 intoltheir former positions and the connection between the con'ipre-ssed airvessel and' the cylinder (j is cut' off and thelatteris ,put

into communication with the outside air so as' to permit the compressedair contained therein toescape ata speedwhich 1s` regulatedby aneedle-valve 30; The springs s will returntlie nijei'iiber o to its.initial posi-'- tion and the` compressor then runs" norin'allyx;V

` {Regarding the air?` cylinder 22s outy along so' thaty slider 23 hasto`travel :ieertain distance iii passing from the posir-y tionl vwhere thecylinder y. communicates -witli'theoutside air to that invwliich itcom-- municatcs with' `the Acoinpressed air-vessel.

without` delay'. Notwithstanding.this it is extremely sensitive forthere vis bata short he base-.plate 20y and Y the cylinder 222. a; paV:ingmay:beinterposed.

- The cams 75mandtliemember oare vcon- Itained nfaja-cket (see'Figs. 1,3, 6, 7 )hav y Ving openings for tliepassage ofthe rollers Y.

*Each of the delivery `valves.f2-11,.c2fhas'a" sliding in `ascrew-threaded pliigc5 thisevei'itually esca-pes by leakff :10b-I piston291.v The various ports This is to' cause the apparatus :to operateplate 03 (see Fig. 4) provided ivithfa rod c* i cylindrical member.

taineiwrf1 castin one with the body of theH ends ofthe cylinder aaresurrounded by,

water jackets fw; (see'Figs. l, 3,4) inlcommunication with .the waterchambers w1 formed `in the heads and surrounding the valves. Theinletand outlet of the cooling water take place `by `the ports'pw?l andw3. The jackets and the chamberspf the ftwo ends are connected by-tlieport w* inthe base and by the Vport on at the topl of Vthe Thelubrication of the diiierentpartsl-of theV compressor isinsured by areservoir a 20 (see Figs. 1,2, 3, 4, 5, 11) containing a lubri.- cantunder pressure. This Vlatter has/,a concylinder a andata removable coverm2 held in place by winged screw plugs yengaging with screw threadedrods z screwed into the base of the reservoir. Into this latter'opens apassagel which starts from the left hand compression chamber and permitsthe desired pressure being obtained inV reservoir and thispassageisprovided with a pointed rregulating screw :fi/and anon-returnyalve 9 (see also Fig. 2). From the reservoir run two portseach meet-ing outside afglass tube each glass tube 3 is connected to apassage l (see also Fig. 10) at each endof theic'ylindern, and servesfor therlubricationthereof screws 5 permit thef-regulationof thev flow Ythrough these passages which is thus lconf vtrolled on'- itsfwayinthetubes 3. Another glass tuber. permits-the level ofthe oil in lthereservoir m to be seenat any moment. Finally there is a fourth glasstube` which .supplies the bearing c2, the-crank lpin and `the large endot' theconnecting rod through a passage S and the medium of the pipe 9,4connected to a passage boredin the interior of the crank shaft. v g

The oil in excessV in the cylinder a is sent back ragain intovthereservoir *.:vby "an oil p pump 10 (see Figsfl, 3, 6), the `piston ofThe which is mounted on the pusher; k2.

'suction side ofl this pump is indicated at 11- land is connected bypipe 1 5 toa passage 1:6 (see alsoiFigQAyin the bottomv ofthe,""cylinder,under therbearing e2.. The' dis,`

"charge off the puinp is indicated at'lQ and is in coimmmicatioi. by apipe 13 with an` Vinlet 'mt (see Fig. l) to the reservoir.' ,Theports-(Z4 in the pistoirwliich provide passage tothe head f of theconnecting rod, prevent isX-:losingin anyl ofits positions the orificeofthepassage 16. One ofthe screw plugs y with ajpres'sure gage 14, asshown in Figs.

may be provided 1 Bolts 17, 18 run from one end to the other sages u2,wJA and serve the purpose of tie rods.

' In consequence 'of the arrangement of the crank shaft e and theconnecting rod 'k inside the piston (Z 4the compressor is double acting,but has neverthelessno stufiing box, and is relatively light becauseithas no piston rod, no cross-head, no slide bars, and no extensionofanykind (bayonet or spoon art) for it and the bearings for theV crankshaft.

The frame contains the'delivery passa-ges,

those for the passage of the cooling water and alsothe space providingpassage for the air drawn in. p

v In order to avoid vibration arrangement may also be made for the axisof the cylinder to he comparatively low.

It the locality where the compressor is situated contains air which issufficiently `pureand veryfresh, the'suction valves may open directlyoutward instead of being connected to passages such as lz; these latterare removable for this purpose.

In order to reduce as: much as possible the Waste space resulting fromthe thickness of the seat of the delivery lvalves,`the body of theselatter may have at its'i center a hollowe'd out enlargement intended topartially till up this space but without howeverhindering the passageoftlie'compressed fluid.

If the compressor is of small power it Ymay be atl-vantagcolvls todivide the cylinder intopt'wo separated parts'on a through-runningdivision-line perpendicularly to the axis of the cylinder and providedywith grooves and tongues, flanges, nutfbolts and set-pins.'`Tlierelatively small weight of the `'single pieces will maketransporting the same on mans back even on high mountains milch easierthan a whole cylinder may be transported. l'

In the case of compressors with small output and therefore of small sizethe cylinder Vmight be left in one piece, but have a larger stroke thaninthe case represented, lforthe same length of cylinder. lTo obtain thishollow parts forming parts ofthe cylinderkmight be provided vabove andbelow ythe axis of the cylinderin the path of the connecting-rod head,said hollows presenting Curved passages 1n the walls of the cylinder forletting pass the head of the connecting rod.

.In other cases the cylinder might present two. bores of differentdiameter, in the larger 1 membersl 32.33,instead. oiy one c3 as shown inFig. Il.l VThe exterior member 32 may be fitted by means ofatlange 321and a pack. ing b2 ony a seatl 32?..providedfwithinthe valve, cam

' shock .bv a cushioning effect.

end a? of the cylinder a. Said member is attached to a hollow rod 324sliding Within a plug c and is subjected to the action of a spring clodged in the rod1324 around arod 327 and bearing at one end on an opendisk 325 located also Within 324 and at the'other end on a Washer 32sfixed to the plug of?.

The rod 327 is fitted with a piston. '3212 mov-V,

ing iii a cylinder 3211iy This member. 32fis provided with'a" seat 321on which thesec.- ond "member, 33', is pressed byV aspring 36.

The member 33 is inone piece With a stem 331 slidably fitted into a bore3211fyofnrxthe rod 324.

At the time of delivery of compressed air the piston l the member 32 islifted from. its seat 323 against the actionfof the sprmg vce and thatof the'. air inclosed in the upperY chamber of the cylinder`3213 andcompressed by piston 3212, so that the 'stopping of said member occursnoiselessly and Without As the delivery of the latter member will notsuflice, the member 33 will also be lifted from its seat 3210. andlifting movement is stopped noise-v lessly and without shock by thecompression v4of the air inclosed within the bo're 321.1 of stem 331.The springs 0G, and 36 may be ing the; piston, an inlet*valve,

a discharge the inlet valve, :'andlmeans by -Which underl ipredetermined Vconditions the. Vsaid vinlet cylinder,-

'valve is opened by the, Said Clm'leViCP/ dur'f lingl hecompressionustroke ofthe piston.v

In a Vcompressor land incomb'ination, a

la' pistontherein, means for *operate-y the piston,` an inlet v valve,la discharge.

va v

e, carni vdevices for normally operating the inlet valveduring thesuctionV stroke V of .the Piston; .determined-.conditionsthe said inletvalve f is opened by the said 'calin devices during the compressionstrokelrof the piston..

and means-.by which underpre- Ina compressor and'n-'combinatiom acylinder, a piston'therem, means for operati. ing the pisto1 1, an inletvalve, a discharge v valve, can-1fdevices-"f'orv operating the inletvalve during the suction stroke of the pis-r ton, 4and cam devicescontrolled` by the pres- .V sure vdeveloped-by the compressor by which AVthe 'said inlet valve'k is opened during 'the Y compression strokeofthe piston When -the i 6s-,pressure has reached a predetermlnedpoint.y

4, VIn a compressor and in combinationa v and in combinatiomacylindenr'a piston thereim'means for operat-l devices for normallyoperating cylinder and a double acting piston therein,l l

within which piston are contained a crank of a driving shaft and aconnecting rod connecting the crank to the piston, suction valvesnormally operatedby a cam, means for. operating :the valves when thepressure lin a compressed fluid reservoirreaches a predetermined value,said vmeans?comprising' rollers rollingov'cra second cam andadapt- .edto be moved aroundtheI latter cani', yet

continuing toy remain incontact' therewitli l Iso that-they may assume aposition inxvhich ythe rollers act on, the valves.

- 5. In a compressorand in combination a cylinder and a` double actingl'piston therein,l

Wit-hin which piston are contained acr'ank lof a driving shaft and aconnecting rodv connectingthe crankto the piston, suction valvesnormally operated by a cam, rollers f rolling over a second cam andadapted to be moved around the lattercam, yet continuing to remain incontact therewitlnand 'spindles connectedy tothe rollers` and yv'vorking.in a` member ada ted to turn about theaXis' of rotation of t e lattercam. f Y i 6. In a compressor and in combination, a cylinder, a doubleacting piston therein` means for driving the piston, cylinder heads,intake valves n each of the cylinder heads,

,discharge valves in each of the cylinderV heads, cam devices foroperating the intake 1valves during the suction stroke of the piston,and cam devices by which the intake valves are automatically openedduring the compression stroke of the piston when the pressure developedby the compressor reaches a predetermined point..

7. In a compressor and'in combination a cylinder and 4a double actingpiston therein,v vWithin which. piston'arejcontained a crank ofa-driving shaft and a connectingl rod concontact therevvith,`y anda memer connected tothe rollers, adaptedto turn about the axis nectingfthecrank to fthe piston, suction valves1 ,A

normally operated' cam,` rollers rolling y over 4afsecondcam-,Yandadapted to be moved v'around-the camfyetcontinuinV to remain 1ny1,10 i

of the cam and operated-in one direction by a piston subjectedto thepressure of `the, compressedrlluid, in theothergby one 'or-more re-Aturn' springs.`

8. Ina compressor and in combination a cylinder and 'a double actingpiston therein,` :withinlwhich piston are contained a crank g'iof'adriving shaft and a connecting rod con- 'Fnecting the crank to thepiston, suctionvalves A'normallyoperatedby ay cam, rollers rolling overa second'cam and adapted to be moved around the cam et continuing toremain in contact therewitli, a member connected lto axis of the cam, apiston operating the rollsure ofthe compressed fluid, and a resilientl1i`1emb' 'rane also subjected vto the pressure ofltherollers andadapted to turnl about the v ers when said piston is subjectedto thepresbrane, on the other side a spring of adjust' the compressed fluidand actuating a control member by means of which either the atmos phericpressure or the pressure of the compressed fluid acts on the piston.V

9. In a compressor and in combination a cylinderand adouble actingpiston; therein, Within which piston are containedy a crank of a drivingsha-ft anda connecting rod con'- necting the crank tothe piston, suctionvalves normally operated by a cam, rollers rolling over a second caniand adapted to be moved Y around the cam yet continuing to remain 1nAcontactV therewith, a member connected to the rollers and adapted toturn about the axis of the calm, a piston operating the rollers whensaidpiston is subjected to the pressure of a lcompressed fluid, and aresilientmembranealsosub'jected tothe pressure of the compressed fluid,a control slide valve operated by the resilient membrane and connectedto a lever, on which act, on the one side of its axis of rotation, theresilient mem-f able tension, and a piston, also connected to the leverand adapted to subjected to the pressure of the compressed Huid. o

10. Ina, compressor and inrcombination a cylinder and a double acting'piston therein. Within which are 'contained a1crank oit' a ldrivingshafttand 'a connecting rod connectingthe crank to the piston, suctionvalves normally operated by a cam, and means `for also opera-ting saidvalveswhen the pressure in a compressed `fluid reservoir reaches apredetermined value, said means being' so arranged `that they producethe opening` of the suction valves during the delivery. stroke of thepiston, this opening taking place howeyer in such a way that there is asmall compression at the end of the stroke. -In testimonywhereof I haveaiixed my signature in presence of two Witnesses.

Witnesses:

. RUSSEM LA CONVERSION,

JUs'r CANI).

EDOUARD BRU AND. y

